ABSTRACT BOOK

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1 INDEX

Committees………. 2

Plenary talks……… 3

Abstracts (by alphabetical order)

Oral presentations……….……….. 8

Poster presentations……….. 151

List of supporters………. 436

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2 COMMITTEES

Conference host

Pyrenean Institute of Ecology, Spanish National Research Council (IPE-CSIC)

Av/ Montañana 1005

50059 Zaragoza

Spain

Phone: +34 976369393

Fax: +34 974363222

www.ipe.csic.es

Local Organizing Committee

Blas Valero-Garcés, Pyrenean Institute of Ecology, CSIC, Zaragoza, Spain

Ana Moreno, Pyrenean Institute of Ecology, CSIC, Zaragoza, Spain

Penélope González-Sampériz, Pyrenean Institute of Ecology, CSIC, Zaragoza, Spain

Graciela Gil-Romera, Pyrenean Institute of Ecology, CSIC, Zaragoza, Spain

José Mª García-Ruiz, Pyrenean Institute of Ecology, CSIC, Zaragoza, Spain

Juan Ignacio López-Moreno, Pyrenean Institute of Ecology, CSIC, Zaragoza, Spain

Jesús Julio Camarero, Pyrenean Institute of Ecology, CSIC, Zaragoza, Spain

Pilar Utrilla, University of Zaragoza (Prehistory), Zaragoza, Spain

Lourdes Montes, University of Zaragoza (Prehistory), Zaragoza, Spain

Rafael Domingo, University of Zaragoza (Prehistory), Zaragoza, Spain

Carlos Sancho, University of Zaragoza (Geology), Zaragoza, Spain

Gloria Cuenca, University of Zaragoza (Geology), Zaragoza, Spain

OSM Scientific Program Committee

Hubertus Fischer, University of Bern, Switzerland

Sheri Fritz, University of Nebraska, USA

Marie-France Loutre, PAGES IPO, Switzerland

Lucien von Gunten, PAGES IPO, Switzerland

Janet Wilmshurst, Landcare Research, New Zealand

Liping Zhou, Peking University, China

Pascale Braconnot, LSCE, France

Hugues Goosse, Université catholique de Louvain, Belgium

Yusuke Yokoyama, University of Tokyo, Japan

Blas Valero-Garcés, IPE-CSIC, Spain

Ana Moreno, IPE-CSIC, Spain

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3 PLENARY TALKS

Wednesday 9:30-10:00

Early onset of industrial-era warming across the

oceans and continents

Nerilie Abram

1

1) Research School of Earth Sciences, The

Australian National University, ACT 2601 Australia

and ARC Centre of Excellence for Climate System

Science, The Australian National University, ACT

2601 Australia

* Nerilie Abram,

The evolution of industrial-era warming provides

critical context for future climate change, and has

fundamental importance for determining climate

sensitivity and the processes that control regional

warming over land and in the oceans. We use

post-1500CE palaeoclimate records to show that

sustained industrial-era warming of the tropical

oceans first developed during the mid-19th

Century, and was near-synchronous with Northern

Hemisphere continental warming. The early onset

of sustained, significant warming in palaeoclimate

records

and

model

simulations

suggests

greenhouse forcing of industrial-era warming

commenced as early as the mid-19th Century, and

included an enhanced equatorial ocean response

mechanism. The development of Southern

Hemisphere warming is delayed in continent-scale

reconstructions, developing around the end of the

19th Century over mid-latitude continents and not

yet evident at the continent scale over Antarctica.

This apparent delay is not reproduced in climate

simulations, but further regional analysis of an

expanded array of Antarctic palaeoclimate records

supports the delayed development of warming

here and may be related to Southern Ocean

circulation processes. Our findings imply that

instrumental

records

are

too

short

to

comprehensively assess anthropogenic climate

change, and in some regions ~180 years of

industrial-era warming has already caused surface

temperatures to emerge above pre-industrial

variability.

Wednesday 10:00-10:30

The future of old things: geoinformatics for

better paleoscience

Julien Emile-Geay

1

, Nicholas P. McKay

2

, Yolanda

Gil

3

, Deborah Khider

1

, Daniel Garijo

3

, Varun

Ratnakar

3

1) Dpt of Earth Sciences, University of Southern

California, Los Angeles, CA, USA

2) School of Earth Sciences and Environmental

Sustainability, Northern Arizona University,

3) Information Sciences Institute, University of

Southern California, Los Angeles, CA, USA

* Julien Emile-geay,

By some accounts, paleoscientists spend up to

80% of their time trying to access the data they

need, in the form they need it. In the 21st century,

we should be able to do much better.This lecture

will review recent progress made by the

LinkedEarth project, which relies on data

standards and artificial intelligence to enable

scientists to spend more time doing the science

they want to do.LinkedEarth is manifesting a

better future for paleoscience by creating an

online platform that (1) enables the curation of a

publicly-accessible database by paleoclimate

experts themselves, and (2) fosters the

development of community standards. In turn,

these developments enable cutting-edge

data-analytic tools to be built and applied to a wider

array of datasets than ever possible before,

supporting more rigorous assessments of the

magnitude and rates of pre-industrial climate

change.We will start by illustrating these

principles in the context of the PAGES2k project,

and outline how they may serve the PAGES

community as a whole. In particular, we will

illustrate how to go from spreadsheets to

syntheses (PAGES2k). We will dwell on community

participation in the first paleoclimate data

standard. We will present GeoChronR and

Pyleoclim, new open-source tools compatible with

these standards and enabling cutting-edge

paleoscience. We will finish by some remarks on

interoperability, enabling cross-talk between

scientists within a field, across fields, and between

data and models.In our vision of the future,

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4 machines serve scientists, not the other way

around. Yet, the process needs a lot of human

input, and the participation of the PAGES

community will be recognized and further

encouraged.

Thursday 9:00-9:30

Determining the causes of climate change: from

large scale temperatures to extreme events

Gabriele Hegerl

1

, Andrew Schurer

1

, Tim Cowan

1

,

Carley Iles

1

, Juerg Luterbacher

1

, Simon Tett

1

1) University of Edinburgh

* Gabi Hegerl ,

Attribution of climate change to causes and

Attribution of changing risk of extreme events

both require reliable information about climate

variability and change. The grand challenge team

on extreme events highlights the need to better

observe, understand, attribute and simulate

extreme events. A short introduction to the

approach of the grand challenge is given, followed

by a discussion of its relevance to palaeoclimate.

Two examples are discussed: Many drought

reconstructions are available and there is

evidence for very significant drought events in the

past. As an example, the historical dust bowl

drought and associated heat waves are compared

to events that occur in climate model simulations.

As a mechanism, sprint moisture preconditioning

appears important, while links to decadal

variability connected to sea surface temperature

appear unclear and model dependent for that

region. When considering a possible role of

external forcing in drought, it is important to

consider the expected pattern of the response,

which can be complex over land. Nevertheless,

long streamflow data support broadly a wettening

of dry regions, and drying of wet regions following

volcanic eruptions. The second example focuses

on extremely cold conditions also following

volcanic eruptions. While overall, reconstructions

tend to show a weaker response to volcanic

eruptions than simulated, some of the most

extreme cold conditions of Europe occurred in the

1810s. Simulations suggest that this period around

the

eruption

of

Mount

Tambora

was

systematically colder than the preindustrial

climate in general. Attribution analyses shows that

the volcanic eruptions are a key driver of these

cool conditions, with only a weak contribution

estimated from solar forcing. However, other

aspects of the cold conditions, for example, in

Central Europe, appear atypical for volcanic

eruptions. Attribution methods can address to

what extent events such as these are random

weather variability, or what fraction of the risk of

cold conditions can be linked to the volcanic

eruption.

Thursday 10:00-10:30

Exploring atmosphere-ocean connections in the

Western Mediterranean region during past

climatic transitions: last terminations, glacial

inceptions and some Holocene key changes

Isabel Cacho

1

, Ana Moreno

2

, Heather Stoll

3

,

OPERA team

4

1) GRC Geociències marines, Dept. Dinàmica de la

Terra i l'Oceà, Universitat de Barcelona

2) Pyrenean Institute of Ecology, CSIC, Zaragoza,

Spain

3) Dept. Erdwissenschaften, ETH Zurich, Zürich,

Switzerland

4) Universitat de Barcelona, Universidad de

Zaragoza, Universidad de Oviedo, Universitat de

les Illes Balears, IPE CSIC, University of Minnesota,

Xian Jiaotong University

* Isabel Cacho,

The Mediterranean region is an exceptional

sensor of climatic variability and in particular, the

western Mediterranean Sea has demonstrated a

tight connection with changes in the Atlantic

Meridional Overturning Circulation (AMOC). Such

a connection is further explored through an

integrated study of cave speleothems and marine

sediments reflecting climate conditions along the

Iberian Peninsula. New speleothem records

covering a transect from the most Atlantic to the

most Mediterranean sectors across the Iberian

Peninsula provide solid chronologies from Marine

Isotopic Stage (MIS) 7 to 4 covering Terminations

III and II and subsequent glacial inceptions. A clear

picture stands out with a strong coupling between

intense aridity phases and cold stadial conditions

linked to AMOC weakening events and also to

changes in the Mediterranean thermohaline

circulation. In contrast, a high resolution Younger

Dryas speleothem record breaks with this overall

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5 stadial pattern showing an intra-event transition

from extreme arid toward wetter conditions

which is linked to circulation changes in the

Atlantic Ocean. Temperature and humidity

changes along the Holocene show a more complex

pattern. A new high resolution W-Mediterranean

surface temperature record supports maximum

temperatures during the early Holocene while

records from the north to the south of Iberia

indicate limited water availability. Maximum in

water availability occurred between 9-7 ka BP

followed by an overall reduction in humidity,

whose timing and pattern changes very much

among the records, likely reflecting different

proxy

sensitivity,

seasonality

or

regional

diachrony. Finally, both speleothem and marine

records show significant variability in temperature

and humidity pattern along the last 2 kyr,

particularly the Little Ice Age appears as a very

unstable climatic period where two different

phases can be differentiated in terms of

temperature and rain patterns, the main driver of

the short term variability of this period seems to

be associated to the Atlantic Multi-decadal

Oscillation.

Thursday 10:00-10:30

Human evolution and climate

Juan Luis Arsuaga

1

1) Universidad Complutense de Madrid

* Juan Luis Arsuaga,

We look around and see all the animals well

adapted to their respective ecological niches. They

have had enough time to adapt. Natural selection,

Darwin´s favorite mechanism for evolution, has

done a good job with them. The unfitted were

eliminated in the struggle for life, long time ago.

Today natural selection should be only a

normalizing force. Then, why do species evolve?

Darwin was well aware of this problem and

thought he had found the solution: the

environment changes. The fittest today could be

misfits tomorrow.In a similar way, climatic and,

consequently, ecological changes haven been

considered a driving force in human evolution. For

the origin of the hominins in the different African

East Side stories, to begin with. And for the rise

and demise of the Neanderthals in the dark and

freezing

European

Ice

Ages.

Neanderthal

specializations have been interpreted as artic

adaptations by some scholars, and yet there are

colleagues who state that Neanderthals could not

survive the Last Glaciation environmental

challenge. They were not outcompeted by

modern humans, it is said, Neandertals went

extinct for just the same reason that other warm

adapted European mammals. Their world

vanished.In this lecture the current evidence for

the role of the climate in the European

Pleistocene hominin evolution is critically revised.

Friday 9:00-9:30

Warm worlds – features and lessons from the

Quaternary interglacials

Eric Wolff and the PAGES Past Interglacials

Working Group

1

1) Department of Earth Sciences, University of

Cambridge, Downing Street, Cambridge, CB2 3EQ,

UK

* Eric Wolff,

Worlds that are warmer than today have a

particular relevance for the future. The Pliocene

had higher CO2 concentrations, comparable to

those of today, but data to infer the climatic

effects are rather sparse. The Holocene has a

wealth of data but rather muted climate changes

in many places. Some Quaternary interglacials

offer a reasonable amount of data on both

forcings and response, and significant differences

in climate. However, interpretation is complex

because the forcings and responses have a

regional character that makes them only partially

analogous

to

anything

expected

in

the

future.Interglacials are warm, low land-ice extent

(high sea–level), end members of glacial cycles.

Concentrating mainly on last 800,000 years, we

first explore different definitions of interglacials to

understand what the population of the species

“interglacial” is. We use a quasi-sea level

definition to identify 11 interglacials in the last

800 ka. Considering both astronomical forcing and

glacial maximum ice volume, we can tentatively

identify why this may be the case.Having

identified the group members, we study their

diversity. Marine, ice and terrestrial data

compilations suggest that, despite spatial

heterogeneity, Marine Isotope Stages (MIS) 5e

(last interglacial) and 11c (~400 ka ago) were

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6 globally strong (warm), while MIS 13a (~500 ka

ago) was cool at many locations. The onset of an

interglacial (glacial termination) seems to require

a reducing precession parameter (increasing

northern hemisphere summer insolation), but this

condition alone is insufficient. Terminations

involve rapid, non-linear, reactions of ice volume,

CO2 and temperature to external astronomical

forcing. The precise timing of events may be

modulated by millennial-scale climate change that

can lead to a contrasting timing of maximum

interglacial intensity in each hemisphere. This will

be illustrated particularly for the case of MIS5e,

and I will emphasise the implications of this

interglacial for ice sheet stability.

Friday 9:30-10:00

Future Earth – vision, mission and opportunities

Hannah Moersberger

1

1) Future Earth, Global Hub in Paris, France

*

Future Earth is a global platform for sustainability

research, aiming at advancing global sustainability

science, building relevant research capacities and

providing

an

international

interdisciplinary

research agenda. The 10-year programme

produces the knowledge and support to

accelerate transformations to a sustainable world.

Future Earth is built on more than three decades

of international research on global environmental

change carried out by projects sponsored by

DIVERSITAS, IGBP and IHDP. PAGES has become

one of Future Earth’s global research projects in

2015.The presentation will give an overview of

Future Earth’s vision and mission, as well as its

current

activities.

Our

Knowledge-Action

Networks as the main mechanism to connect

science with society invite researchers from all

kinds of disciplines and backgrounds to get

engaged. Their scope covers a broad range of

topics, from oceans and natural assets to

transformations, the SDGs and financial and

economic systems.

Saturday 17:15-17:45

New observations of past, fast changes in

greenhouse gases

Edward Brook

1

, Rachael Rhodes

2

, Shaun

Marcott

3

, James Lee

1

, Jon Edwards

1

, Thomas

Bauska

2

, Jinho Ahn

4

, Michael Kalk

1

, Jochen

Schmitt

5

, Hubertus Fischer

5

1) College of Earth, Ocean, and Atmospheric

Sciences, Oregon State University, Corvallis, OR,

USA

2) Department of Earth Sciences, University of

Cambridge, Cambridge, UK

3) Department of Geoscience, University of

Wisconsin, Madison, WI, USA

4) School of Earth and Environmental Sciences,

Seoul National University, Seoul, Korea

5) Climate and Environmental Physics, Physics

Institute & Oeschger Centre for Climate Change

Research, University of Bern, Bern, Switzerland

* Edward Brook,

Advances in measurement technology and new

archives now allow the resolution of ice core gas

records to approach or exceed the atmospheric

lifetimes of methane, carbon dioxide, and nitrous

oxide. Detail at this level provides insight in to

mechanisms that control natural variability and

feedbacks in the climate system on time scales

relevant to human impacts on the earth system.

This presentation provides an overview of new

carbon dioxide and methane results, primarily

from the WAIS Divide ice core in Antarctica, that

reveal new aspects of the relationship between

abrupt climate change and greenhouse gas

biogeochemistry.

Continuous

records

of

atmospheric methane from WAIS Divide fully

document the well-known variations tied to the

Greenlandic stadial-interstadial variability, linked

by multiple lines of evidence to changes in low

latitude methane emissions. This and other

records also reveal a) abrupt shifts in the baseline

methane concentration during some Heinrich

stadials, probably tied to the impact of Heinrich

events on tropical hydrology, and b) persistent but

enigmatic centennial variability in the Holocene

and last glacial period. Carbon dioxide variations

during the last ice age and deglaciation generally

correlate with Antarctic temperature, but in detail

seem comprised of variability on different time

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7 scales. Coincident, abrupt increases in methane

and carbon dioxide during some Heinrich stadials

delineate a new type of abrupt event, probably

related to southward migration of tropical rainfall

belts causing increased methane emissions. The

synchronous carbon dioxide variations could also

have a terrestrial source, for example due to

drying in the northern tropics, but there are viable

mechanisms linked to changes in ocean circulation

or biogeochemistry.

Saturday 17:45-18:15

Climate variability, vegetation dynamics and

human-environment

in

continental

Mediterranean Iberia during last glacial cycle

Penélope González‐Sampériz

1

1) Pyrenean Institute of Ecology-CSIC, Av/

Montañana s/n, 50059 Zaragoza (Spain)

*

The inland areas of Mediterranean Iberia are

vulnerable regions to Global Change impacts as

they are characterized by extreme climate

conditions in terms of both temperature and

precipitation. Humans have faced abrupt

environmental and climate changes in these

territories through the last glacial cycle and those

synergies illustrate the PAGES initiative: the

climate-humans-environment

interactions

through time.New records have changed our

understanding

of

the

palaeoenvironmental

framework for inner Iberia during the last glacial

cycle. The current complex biogeographical

context of the Iberian Peninsula is a reflection of a

complex palaeoenvironmental history, with

unexpected trends and impacts in both vegetation

landscape and hydrological processes, compared

with coastal areas, Atlantic and more typical

Mediterranean regions. Patterns of cultural and

socioeconomic evolution also show distinctive

characteristics.Not

surprisingly,

terrestrial

vegetation in continental Iberia shows a resilient

behaviour during millennial – scale evolution and

short periods of abrupt climate change, despite,

interestingly, nearby locations respond as

expected to abrupt changes with similar evolution

in terms of taxa composition to Mediterranean

and/or Eurosiberian sites. Besides, vegetation

dynamics usually followed local, or even regional,

palaeohydrological conditions but not always

global

millennial-scale

climate

variability.

Asynchrony in both timing of the local last glacial

maximum and humidity onset at the beginning of

the Holocene are two clear examples of this

complex scenario. Additionally, hunter-gathered

groups likely responded to abrupt events with

migration episodes, but there are too a number of

examples of diverse responses to hydrological

crises during deglaciation and the Holocene.

Timing and intensity of first anthropogenic impact

is also very variable along the whole territory.All

these "apparent inconsistencies" are probably the

result of an incomplete record but also illustrate

the

great

heterogeneity

inherent

to

Mediterranean regions. Interpretations of past

human interactions with the landscape become

more difficult in regions with extreme events,

resilient vegetation and variable landscape

dynamics. But they also provide an opportunity to

improve our knowledge about Earth’s past

environment at local-regional scales, in order to

obtain better and more detailed scenarios of

human interactions with future climate and

environment changes, as PAGES promotes and

society demands.

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8 ORAL PRESENTATIONS

(by alphabetical order of first author surname)

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9

ID: 02156, 08.- Volcanic eruptions: the thread connecting climate records, societal change and future climate projections?, (Oral)

¬Tracing Marine Cryptotephras in the North Atlantic during the Last Glacial Period

Peter Abbott1 , Siwan Davies2 , Adam Griggs2 , Anna Bourne3 1) Institute of Geological Sciences, University of Bern, Switzerland and School of Earth and Ocean Sciences, Cardiff University, UK 2) Department of Geography, Swansea University, UK 3) Geography and Environment, University of Southampton, UK * Peter Abbott, [email protected]

There is high potential to utilise tephrochronology to integrate palaeoclimatic records from the North Atlantic region to study climatic phasing, due to the high eruptive frequency of Icelandic volcanoes. However, until now North Atlantic marine records have been relatively understudied. Here we report on investigations to define a tephra framework integrating new studies of cryptotephra horizons within a wide network of marine cores with horizons identified in prior work. This framework has the potential to underpin the correlation of the marine records to the Greenland ice-core records and European terrestrial sequences.

Investigations were conducted on 13 marine sequences using cryptotephra extraction techniques to gain glass shard concentration profiles and single-shard major element geochemical analysis to characterise identified deposits. Cryptotephras were identified in many records, displaying diversity in shard concentration profiles and geochemical homo/heterogeneity. These differences reflect spatial and temporal variability in the operation of a range of transport processes, e.g. airfall, sea-ice and iceberg rafting, and post-depositional processes, e.g. bioturbation and secondary redeposition. These processes can impart a temporal delay on tephra deposition and hamper the placement of the isochron, therefore, their influence is assessed. A range of deposit types with common transport and depositional histories have been defined. Spatial patterns in the occurrence of these deposit types have been detected, the dominant controls at different sites explored and key regions preserving isochronous deposits identified.

Overall, a framework of isochronous marine cryptotephras has been defined for the last glacial period. The most widespread deposit is the rhyolitic phase of NAAZ II, identified in 9 of the marine sequences and providing a direct tie-line to the Greenland ice-cores records. The framework is dominated by horizons with a basaltic composition, predominantly sourced from the Icelandic Grímsvötn volcanic system but horizons with Katla, Hekla, Kverkfjöll, Veidivötn and Vestmannaeyjar-like compositions have also been isolated.

ID: 01945, 14.- Hydroclimate variability through the ages: Data, models, mechanisms, (Oral)

Indian Ocean Dipole variability during the last millennium

Nerilie Abram1 , Bethany Ellis1 , Bronwyn Dixon2 , Wahyoe Hantoro3 , Chuan-Chou Shen4 1) Research School of Earth Sciences and ARC Centre of Excellence for Climate System Science, Australian National University, ACT 2601, Australia 2) School of Geography, University of Melbourne, Victoria 3010, Australia 3) Research Centre of Geotechnology, Indonesian Institute of Sciences, Bandung 40135, Indonesia 4) High-precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan ROC * Nerilie Abram, [email protected]

The Indian Ocean Dipole (IOD) is a mode of coupled ocean-atmosphere variability that severely impacts rainfall patterns in nations surrounding the Indian Ocean. Coral-based reconstructions of IOD variability since the mid 19th Century suggest that there has been a significant increase in the frequency and magnitude of positive IOD events in recent decades. Climate model simulations also indicate that the rainfall impacts of extreme IOD events will intensify in a warming world, however confidence is limited by known biases in model representations of the IOD. Here we use an array of fossil coral records from the eastern equatorial Indian Ocean – where the signature of IOD variability is optimised – to produce a semi-continuous reconstruction of IOD variability during the last millennium. This reconstruction includes coverage during the Medieval Warm Period, Little Ice Age and pre-industrial periods, as well as following major volcanic eruptions of the last millennium. We use these records alongside ensembles of climate simulations to assess the factors that have caused changes in the frequency and characteristics of IOD variability in the past, and to provide valuable perspectives on the apparent and predicted intensification of IOD activity during the 20th and 21st Centuries.

ID: 01241, 24.- Regional versus global in past monsoon dynamic: disentangling wind and precipitation proxies., (Oral)

Late Quaternary record of changes in the planktonic foraminiferal abundance in the north to south transect of the Andaman Sea: inferences on monsoon climate Sijinkumar Adukkamveedu1 , B N Nath2 , Steven Clemens3 , S M Ahmad4 , S M Gupta2 , A Aldahan5 , G Possnert6 , N Lathika7 1) Department of Geology, School of Earth Science Systems, Central University of Kerala, Kerala , India 2) CSIR-National Institute of Oceanography, Dona Paula, Goa, India 3) Earth, Environmental, and

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10

Planetary Sciences, Brown University, Providence, RI, USA 4) CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad, India 5) Department of Earth Sciences, Uppsala University, Uppsala, Sweden 6) Tandem Laboratory, Uppsala University, Uppsala, Sweden 7) National Centre for Antarctic and Ocean Research, Vasco Da Gama, Goa, India * Sijin Kumar Adukkam Veedu, [email protected]

Late Quaternary climate and oceanographic conditions of the Andaman Sea is rarely studied and the available paleo records are limited to oxygen isotopic and magnetic properties. We present here the downcore variations in planktonic foraminifera assemblages along with oxygen isotope and geochemical proxies of three well-dated cores collected from the north–south transect of the Andaman Sea. Age controls of the cores are based on accelerator mass spectrometry (AMS) dates on mixed planktonic foraminifera. The proxy profiles show glacial-Holocene millennial scale monsoonal climate changes and associated productivity fluctuations. Large variations in river runoff, productivity and water column stratification is seen associated with summer monsoon evolution from last glacial to Holocene. Intensification of the summer monsoon started in the early stages of the Bølling/Allerød (B/A; 15-13.5 ka) followed by slight weakening during the Younger Dryas (YD) and regained strength during early Holocene, coinciding with the highest summer insolation at 30˚N. This enhanced summer monsoon during early to mid-Holocene resulted in huge fresh water runoff that slowly muted upwelling and productivity by intense stratification. Summer monsoon was weaker during Heinrich Event 1 (H1), late Glacial (19-16 ka), Last Glacial Maximum (LGM), 38 – 34 cal ka BP and 46-41 cal ka BP. A progressive gradual decline in the total planktic foraminifera abundances from early Holocene to present suggests a gradual weakening of the summer monsoon. Our records show that monsoon variability in the last 55 ka has been controlled by variation in solar insolation, Atlantic teleconnection on Heinrich and Dansgaard-Oeschger time scale and finally shifting feedback associated with summer-winter monsoon interaction.

ID: 01715, 16.- Multidisciplinary reconstruction of paleofloods, (Oral)

Late Pleistocene outburst floods of the ice-dammed lakes and climate changes in the highlands of the SW Tuva, mountains of Southern Siberia

Anna Agatova1 , Roman Nepop1 1) Institute of Geology and Mineralogy 2) Ural Federal University * Anna Agatova, [email protected]

We present the results of our multidisciplinary investigations of the SW Tuva highlands, which is the watershed of two basins: the Arctic Ocean and the inland drainage basin of Mongolia. During Pleistocene

glaciations, glaciers extended repeatedly from the mountain ranges along the major valleys and impounded extensive lakes within the depressions. Subsequent ice-dam failures led to outburst floods. All these processes were controlled by the Global climate changes and are evidenced by numerous specific landforms and sediments.In the framework of presented study generally 11 sections were studied and 15 new radiocarbon ages of deposits of different genesis were obtained.

New data suggest the existence of significantly larger lakes in the region. We also present evidences of the outbursts floods from these ice-dammed lakes and describe landforms and sediments associated with these flooding events.

Available absolute dates suggest some chronological stages of the late Pleistocene – Holocene regional hydrological system transformation controlled by climate changes. Period of prolonged climate deterioration followed by the development of spacious glaciations and related formation of ice-dammed lakes took place earlier 14000 years ago. Early Holocene climate warming accompanied by degradation of the ice sheet determined further stages of ice-dammed lakes development and draining. We can state that no later than 8000 years ago the water level in some lakes significantly declined and after their final drying approximately to the modern size there were only climatically driven oscillations of their filling.

Favorable climate conditions (more warm and humid in comparison with the modern ones) about 3000-3500 years ago was evidenced by soil formation and wide spread of forest vegetation in treeless modern landscape of the region. In 6th – 2nd centuries BC the area was widely settled by nomads associated with the Saglyn culture of Scythian epoch.

ID: 01404, 19.- Do species move, adapt or die? Exploring past biodiversity, ecological change and community dynamics in the fossil record, (Oral)

The Pleistocene fish fauna along the eastern coast of Rhodes Island (eastern Mediterranean)

Konstantina Agiadi1 , Angela Girone2 , Efterpi Koskeridou1 , Pierre Moissette3 , Jean-Jacques Cornée4 , Frédéric Quillévéré3 , Vasileios Karakitsios1 1) National and Kapodistrian University of Athens 2) Università degli studi di Bari 3) Université Lyon 1 4) Université

Montpellier 2

* Konstantina Agiadi, [email protected] teleost assemblages identified in the Pleistocene sediments of the eastern part of Rhodes Island (southeastern Aegean Sea) exhibit a similar structure to the present-day eastern Mediterranean ones. Epipelagic fish include anchovies, sardines, and horse mackerels, whereas lanternfishes dominate the mesopelagic domain. The most numerous

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and diverse benthic and benthopelagic families are congrids, gadids, sparids, and gobiids. A gradual replacement of pelagic tropical-subtropical species by subtropical-temperate ones, in both the neritic and the oceanic domain, took place from the Gelasian until the Ionian stage. The distribution of pelagic taxa during the Pleistocene appears to be mostly related to climate variability at local and global scale. However, the benthic neritic community did not suffer as well, since most of the species remain present in the southeastern Aegean until today. In the deep water, benthic and benthopelagic taxa have been gradually removed from this area, favoring colder-water inhabitants. The otolith assemblages identified in the Pleistocene sediments of Rhodes Island significantly enhance the eastern Mediterranean fish fauna Cenozoic record, which has so far relied only on scarce and fragmentary skeletal remains.

Frequent extreme rainstorms during late Holocene regional drought in the Dead Sea basin

Marieke Ahlborn1 , Moshe Armon2 , Yoav Ben Dor2 , Achim Brauer1 , Efrat Morin2 , Ina Neugebauer3 , Markus J. Schwab1 , Rik Tjallingii1 , Yehouda Enzel2 1) Section 5.2: Climate Dynamics and Landscape Evolution, GFZ German Research Centre for Geosciences, Potsdam, Germany 2) Institute of Earth Sciences, The Hebrew University, Jerusalem, Israel 3) Department of Earth Sciences, University of Geneva, Geneva, Switzerland * Marieke Ahlborn, [email protected]

Linking the frequency of extreme-flow-producing rainstorms and the long-term climate trends is essential for assessing the impacts of global and regional climate change. Our results present rare evidence of increased frequency of torrential rainstorms likely associated with the Active Red Sea Trough during a multi-century regional drought in the eastern Mediterranean.

We studied a shallow water sediment core from the Dead Sea to establish a time series of torrential rainstorms for the time interval between 3.3 and 1.8 cal ka BP. Microfacies analysis allowed the identification of 23 discrete graded layers formed by debris flows originating from the nearby steep western escarpments of the Dead Sea. Modern observations show that debris flows are triggered by exceptionally heavy torrential rainstorms over the escarpments, which exceed an estimated threshold of at least >30 mm h-1 for the duration of one hour. Such rainstorms are synoptically associated with the intrusion of the Active Red Sea Trough into the Dead Sea catchment. An increased frequency of torrential rainstorms during a regional drought (3.0-2.4 cal ka BP), as suggested by our data, indicates a shift in the prevailing synoptic-scale atmospheric circulation pattern.

In particular, we suggest that the drought was caused by a decreased frequency of eastern Mediterranean cyclones and thereby allowed the increased frequency of the Active Red Sea Trough triggering the torrential rainstorms during generally drier conditions. Detailed analyses of present-day data from nearby gauging stations confirm that severe rainstorms become more frequent during droughts, and provide more conclusive evidences for late Holocene shifts in synoptic atmospheric circulation patterns. Our late Holocene sediment record from the Dead Sea provides a valuable record of torrential rainstorms, their causative synoptic conditions, and their linkage to the underlying long-term climate trend in the eastern Mediterranean.

ID: 01973, 32.- Large-scale hydroclimate variability and change of the Common Era: Patterns, Impacts, and Processes, (Oral)

Reconstructions of winter and summer hydroclimate in western Tasmania

Kathryn Allen1 , Robert Evans1 , Edward Cook1 , Stuart Allie1 , Fiona Ling1 , Greg Carson1 , Patrick Baker1 1) University of Melbourne, Silviscan Pty Ltd, Lamont Doherty Earcth Obervatory, HydroTasmania, Entura * Kathryn Allen, [email protected]

Water resource availability is critical for agriculture, environmental flows, hydroelctric energy production and supply of drinking water. In Australia, short and sparse instrumental records, most of which span < 100 years, limit understanding of hydroclimatic variability. Here we present two seasonal hydroclimatic reconstructions for western Tasmania in southeastern Australia (SEA). In this region water resources are managed on a seasonal basis and there is often little relationship between the hydroclimate of different seasons. Both reconstructions are based on a mixture of ring width and wood properties chronologies (e.g. tracheid radial diameter, cell wall thickness, density, microfibil angle). The first and longest, is a 960-year December - February dam inflow reconstruction. The model explains ~37% of the variance in the calibration period and ~48.5% in the verification period. The reconstruction suggests that summer inflows since ~1900 have generally been close to or below average over the past millennium. The longest dry period occurred around 1500 CE and was accompanied by mean summer temperatures that were well above average. Greater variability is apparent between about 1550 and 1750 CE. The second reconstruction, for the winter period (July-August), is much shorter and also weaker than the summer reconstruction, but verifies back to 1731. It explains ~23% of the variance in inflows and, somewhat unusually, better captures wet rather than dry periods. According to the reconstruction, winters for the past ~150 years have been drier than for the previous ~150 years. Conditions more extreme than those in the

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20th Century have occurred in the past for both seasons. Differences in the reconstructions demonstrate the relevance of highly resolved seasonal information in regions such as SEA, and temperature reconstructions for the same region and season will facilitate more detailed analyses of long-term hydroclimate than have previously been possible for this region.

ID: 02142, 13.- Pliocene climate variability over glacial-interglacial timescales (PlioVAR), (Oral)

Late Pliocene-Early Pleistocene oscillations in Mediterranean Overflow water and climate in the Iberian Margin

Montserrat Alonso-Garcia1 , Emilia Salgueiro1 , Teresa Rodrigues1 , Carlos A. Alvarez-Zarikian2 , Warley Soares1 , Ana I. Lopes1 , Henning Kuhnert3 , Ursula Röhl3 , Antje H.L. Voelker1 , Francisco J. Sierro4 , Jose A. Flores4 , Fátima Abrantes1 1) Centro de Ciências do Mar (CCMAR), Universidade do Algarve, 8005-139 Faro, and Instituto Portugues do Mar e da Atmosfera (IPMA), Avda Alfredo Magalhães Ramalho 6, 1495-006 Lisboa, Portugal 2) International Ocean Discovery Program, Texas A&M University, Discovery Drive, College Station, TX 77845, USA 3) University of Bremen, Leobener Str., Marum, 28359 Bremen, Germany 4) Universidad de Salamanca, Pza de la Merced s/n, 37008, Salamanca, Spain * Montserrat Alonso-

Garcia, [email protected]

The Late Pliocene-Early Pleistocene transition is characterized by a climatic cooling that boosted the expansion of ice-sheets in the Northern Hemisphere and brought the alternation between glacial and interglacial periods. Several hypotheses have been put forward to explain this climate transition, and recently, changes in the production of Mediterranean deep water have been suggested to be an important factor during this transition since this deep water mass contributes high salinity water to the North Atlantic enhancing the whole Atlantic Meridional overturning circulation.

Here we investigated the oscillations in Mediterranean overflow water (MOW) throughout the Late Pliocene and Early Pleistocene using sedimentological and paleontological data from Site U1391 (37° N; 9° W; 1085 m water depth), recovered on the Southwest Iberian Margin during the Integrated Ocean Drilling Program (IODP) Expedition 339. This site is located in a plastered drift in the path of the MOW and offers high sedimentation rates to perform not only high resolution studies of past oceanographic conditions but also to reconstruct climate variability in the region across this transition. In this study, we provide the chronological framework for the bottom part of Site U1391 and combine records of XRF geochemical data (from X-ray fluorescence core scanning), grain-size analysis, benthic foraminifer δ18O and δ13C, and benthic assemblages

(ostracod and foraminifers) to evaluate changes in deep water circulation. Moreover, we reconstructed sea surface temperature conditions to assess the coherence between the regional climate and MOW. The high-resolution record of the XRF analysis (Zr/Al) indicates short-term MOW oscillations very likely related to a precessional pattern, as previously shown for the Mid-Late Pleistocene. However, the grain-size analysis shows a decreasing trend across the study interval, which indicates long-term changes in MOW. Early Pleistocene glacial-interglacial cycles appear to show a stronger coupling between MOW oscillations and sea surface conditions.

ID: 01605, 33.- Ancient DNA for understanding past biodiversity, human history, and drivers of ecosystem changes: achievements, limits and perspectives, (Invited Oral)

Application of HyRAD-X (a method combining reduced representation of the exome and hybridization capture applied to ancient DNA) to time series of subfossil needles unravels the early Anthropocene history of the silver fir, Abies alba, in a population from the southern Alps

Nadir Alvarez1 , Sarah Schmid1 , Christoph Sperisen2 , Willy Tinner3 1) Department of Ecology and Evolution, Biophore Building, UNIL-Sorge, University of Lausanne, 1015, Lausanne, Switzerland 2) Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland 3) Institute of Plant Sciences and Oeschger Centre for Climate Change Research, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland

* Nadir Alvarez, [email protected]

Our understanding of the evolution of several emblematic species across millenia has considerably increased in the last decade, thanks to the application of whole-genome capture, in combination with next-generation sequencing. However, to our knowledge, only anecdotical studies have made use of the application of those methods to the impressive time series of tree subfossils available in lake sendiments, to unravel the late Pleistocene and Holocene evolutionary history of forest species. One of the explanations to this gap is the lack of proper reduced genomic representation technique allowing to analyze a large number of ancient DNA samples without applying costly whole-genome capture methods.Here, we present a major update to those methods, namely Hybridization capture from (messenger) RNA to RNA (probes) using RAD-derived probes (HyRAD-X), a technique applying RAD-sequencing to messenger RNA from one or few fresh specimens to elaborate bench-top produced probes, i.e., a reduced representation of the exome, further used to capture homologous DNA from a samples set. As a proof of

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concept, we applied HyRAD-X to subfossil needles from the tree Abies alba, collected in lake sediments at Origlio (Switzerland) and dating back from 7200-5800 years before present (BP). More specifically we investigated genetic variation before, during, and after an anthropogenic perturbation that caused an abrupt decrease in Abies alba population size, 6500-6200 years BP. HyRAD-X produced a matrix encompassing 524 exome-derived SNPs. Despite a lower observed heterozygosity was found during the 6.500-6.200 years BP time slice, genetic composition was nearly identical before and after the perturbation, indicating that re-expansion of the population after the decline was driven by autochthonous specimens. This study outperforms by orders of magnitude previous studies exploring the potential of tree subfossil samples in population genomic studies.

ID: 01940, 03.- Regional and transregional climate variability over the last 2000 years, (Oral)

Common Era temperature reconstructions and the response of the climate system to explosive volcanic eruptions

Kevin Anchukaitis1 , Rob Wilson2 , Jessica Tierney3 , Allegra LeGrande4 , NTREND Consortium5 , PAGES2k Oceans2k HR6 1) School of Geography and Development and Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, USA 2) School of Geography and Geosciences, University of St Andrews, UK 3) Department of Geosciences, University of Arizona, Tucson, AZ, USA 4) National Aeronautics and Space Administration Goddard Institute for Space Studies, New York, NY, USA 5) Northern Hemisphere Tree-Ring Network Development (NTREND) Consortium 6) Past Global Changes (PAGES) 2k

Consortium (Oceans2k)

* Kevin Anchukaitis, [email protected] Volcanic eruptions cause global-scale changes to the climate system via the direct effect of radiative forcing anomalies and the ensuing influences on and feedback to major modes of ocean-atmosphere variability. Climate model simulations suggest a larger degree of cooling following eruptions than proxy temperature reconstructions, and disagreement persists about the subsequent state of the El Nino Southern Oscillation system. Here, we use two recent temperature reconstructions to investigate the response of the climate systems to volcanic eruptions. Our new NTREND field reconstruction of Northern Hemisphere summer temperatures shows coherent, broad-scale cooling associated with large tropical eruptions: 96% of reconstructed grid points show composite mean colder temperatures and an average response across all grid points and all eruptions of -0.44C. Cooling persists in some cases for 2 or more years following eruptions and different eruptions reveal different magnitudes and

spatial patterns that are not clearly associated with estimated radiative forcing. The PAGES2k Oceans2k High Resolution (HR) reconstruction of tropical sea surface temperatures shows cooling of the western Pacific and Indian Ocean in response to well-dated tropical eruptions since 1600 CE but no statistically significant response in the eastern tropical Pacific, suggesting a reduction in the tropical Pacific temperature gradient but not a canonical El Nino pattern. Climate models simulate an overall larger cooling in the western Pacific and Indian Ocean than the reconstructions and produce a variety of anomalies in the eastern Pacific. Our results here provide a new benchmark comparing proxy reconstructions and model simulations and may help identify possible sources of disagreement.

ID: 01779, 04.- From the Mediterranean to the Caspian: palaeoclimate variability, environmental responses and human adaptive strategies, (Oral)

Holocene Paleoenvironmental Change in the Sierra Nevada, Southern Spain

R. Scott Anderson1 , Gonzalo Jiménez-Moreno2 , Antonio García-Alix2 , Francisco Jiménez Espejo3 , Jaime Toney4 , María Ramos-Román2 , Jose Carrión5 , Carmen Pérez-Martínez6 , María Hernández-Corbalán2 1) School of Earth Sciences & Environmental Sustainability, Northern Arizona University, USA 2) Departamento de Estratigrafía y Paleontología, Universidad de Granada, España 3) Department of Earth and Planetary Sciences, Nagoya University, Japan 4) Geographical & Earth Sciences, University of Glasgow, UK 5) Departamento de Biología Vegetal, Universidad de Murcia, España 6) Departamento de Ecología, Universidad de Granada, España * R. Scott Anderson, [email protected]

The Sierra Nevada region of southern Spain has a rich biological and cultural heritage. Recent paleoenvironmental research in the range includes sedimentary records from several high elevation lakes and bogs, spanning an elevational range of ca. 2500 m to over 3000 m elevation. Common research themes have centered around (1) the impact of climate change and human land use on the fragile alpine ecosystems, as well as (2) the record of more regional human impact on lower elevation landscapes surrounding the mountain range.

The longest (~ 11,500-yr) record comes from the 3020 m asl Laguna de Río Seco (LdRS), where paleobotanical, isotope geochemical and organic biomarker data suggest wet conditions prior to ~ 7.8 ka, and much drier climates after ~ 5.7 ka. These changes are confirmed from additional sites in the range. Progressive aridification of the mid- through late Holocene was periodically interrupted by wetter conditions, such as the widespread Roman Humid Period.

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Signals of human activity within the region and locally within the range are evident in the cores. For example, increases in Pb in sediment occurs during the Early Bronze Age, ~ 3.9 ka. Regionally, increases in charcoal deposition ~ 4.0 ka may result from these activities, rising population levels with changing land-use, or climatic factors. Increasing Olea pollen after ~ 3.0 ka may signify the beginnings of olive cultivation at lowland sites, with major expansion of olive orchards during the 20th century. The periodic Holocene occurrence of the dung fungus, Sporormiella becomes more consistent after ~ 3.0 ka suggest more intensive pasturing. Though Pinus dominated during the early Holocene, it largely disappeared in the pollen record at about this time, suggesting widespread tree-cutting. Only with the establishment of Pinus plantations during 20th century does pine return to importance there.

400 years of summer hydroclimate from stable isotopes in Iberian trees

Laia Andreu Hayles1 , Caroline C. Ummenhofer2 , Mariano Barriendos3 , Gerhard H. Schleser4 , Gerhard Helle5 , Markus Leuenberger6 , Emilia Gutiérrez7 , Edward R. Cook1 1) Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA. 2) Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA, USA. 3) Department of History and Archaeology, University of Barcelona, Barcelona, Spain 4) Climate Dynamics and Landscape Evolution, German Centre for Geosciences, Potsdam, Germany. 5) Research Center Juelich, Institute of Bio-and Geosciences, Agrosphere (IBG-3); Juelich, Germany. 6) Climate and Environmental Physics, University of Bern, Switzerland. 7) Department of Ecology, University of Barcelona, Spain. * Laia Andreu Hayles, [email protected]

Tree rings are natural archives that annually record distinct types of past climate variability depending on the parameters measured. Here, we use ring-width and stable isotopes in cellulose of trees from the northwestern Iberian Peninsula (IP) to understand regional summer hydroclimate over the last 400 years and the associated atmospheric patterns. Correlations between tree rings and climate data demonstrate that isotope signatures in the targeted Iberian pine forests are very sensitive to water availability during the summer period, and are mainly controlled by stomatal conductance. Non-linear methods based on extreme events analysis allow for capturing distinct seasonal climatic variability recorded by tree-ring parameters and asymmetric signals of the associated atmospheric

features. Moreover, years with extreme high (low) values in the tree-ring records were characterised by coherent large-scale atmospheric circulation patterns with reduced (enhanced) moisture transport onto the northwestern IP. These analyses of extremes revealed that high/low proxy values do not necessarily correspond to mirror images in the atmospheric anomaly patterns, suggesting different drivers of these patterns and the corresponding signature recorded in the proxies. Regional hydroclimate features across the broader IP and western Europe during extreme wet/dry summers detected by the northwestern IP trees compare favourably to an independent multicentury sea level pressure and drought reconstruction for Europe. Historical records also validate our findings that attribute non-linear moisture signals recorded by extreme tree-ring values to distinct large-scale atmospheric patterns and allow for 400-yr reconstructions of the frequency of occurrence of extreme conditions in summer hydroclimate. We will discuss how the results for Lillo compare with other records.

Vegetation dynamics and hydrological response to Holocene climate variability in the Iberian Range: a synthesis from lacustrine and tufa records

Josu Aranbarri1 , Penélope González-Sampériz 2 , Blas Valero-Garcés2 , Ana Moreno2 , Carlos Sancho3 , Graciela Gil-Romera2 , Miguel Bartolomé2 , Marta Alcolea4 , Mª José González-Amuchastegui 1 , Concha Arenas3 , Maria Leunda2 , Donatella Magri5 1) Department of Geography, Prehistory and Archaeology, University of Basque Country 2) Department of Geoenvironmental Processes and Global Change, Pyrenean Institute of Ecology-CSIC 3) Department of Earth Sciences, University of Zaragoza 4) Department of Antiquity Sciences, University of Zaragoza 5) Department of Environmental Biology, Sapienza University of Rome

* Josu Aranbarri, [email protected]

The increase in chronologically well-constrained, palynological, sedimentological and geomorphological sequences obtained from lacustrine and fluvial tufa records along the Iberian Range (NE Spain) has allowed to drawn the vegetation dynamics and the hydrological variability during the Holocene. Overall, three main phases of environmental change can be established. 1) The early Holocene, chronologically comprising 11.700-8200 cal yr BP, is defined as a landscape dominated by montane pinewoods (e.g., Pinus sylvestris/nigra type) and steppe communities (e.g., Artemisia, Compositae, Chenopodiaceae), suggesting a harsh continental climate background. Palaeohydrological proxies reveal low water-stands till 9500 cal yr BP. 2) The most humid phase during

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the Holocene occurred between ca. 8200-5000 cal yr BP and was characterized by the maximum spread of broadleaved elements (e.g., Betula, Corylus, Quercus faginea type), the expansion of a Mediterranean woodland with evergreen Quercus as dominant forest communities and more frequent periods of higher lake levels, resulting in the maximum frequency of tufa deposition at regional-scale. 3) The return of montane pinewoods synchronous to the depletion of broadleaved trees and the decline of tufa growing characterize the mid-late Holocene transition (ca. 5000 cal yr BP). This transition was most likely a consequence of increasing aridity that continued during the late Holocene. Human-pressure is practicably negligible until Roman-times when a rapid region-wide deforestation and the spread of agriculture occurred.

ID: 01363, 01.- Open Session on past global changes, (Oral)

Mean ocean temperature evolution in the past 40,000 years from ice core noble gas thermometry

Daniel Baggenstos1 , Marcel Haeberli1 , Thomas Kellerhals1 , Jochen Schmitt1 , Hubertus Fischer1 1) Climate and Environmental Physics & Oeschger Center for Climate Research, University of Bern * Daniel Baggenstos, [email protected] amount of heat stored in the ocean is the most robust measure of the integrated energy imbalance of the Earth that accompanies glacial-interglacial climate swings. For the current anthropogenic warming, more than 90% of the excess heat stored by the Earth over the last 50 years is found in the ocean.The history of ocean heat content is thus a central parameter in the reconstruction of global climate forcing and response. Local deep water temperature has been reconstructed using sediment cores, but a truly global signal is difficult to synthesize. The novel method of ice core noble gas thermometry allows us to reconstruct global mean ocean temperature (GMOT) based on simple physics. Because noble gases are passively cycled through the atmosphere/ocean system, and because each gas species has a specific temperature dependent solubility, noble gas ratios in the atmosphere represent a direct, physical proxy for GMOT. After correcting for fractionation effects that happened in the firn column prior to the air getting trapped in the ice matrix, measurements of noble gas elemental ratios in ice cores can thus be used to estimate past GMOT.We present a record of GMOT obtained from EDC ice core samples spanning the last 40,000 years in roughly 1,000 year resolution, highlighting the warming during the deglacial transition. The Last Glacial Maximum GMOT is estimated to 2.6°C colder than present, in good agreement with sediment core oxygen isotope and pore water fluid reconstructions. The early Holocene was slightly warmer than present by approximately 0.5°C. The

GMOT record shows a remarkable correlation with Antarctic temperature, suggesting that the Southern Ocean is an important driver of temperature change in the deep ocean.

Paleoflood Data and Increasing Flood Extremes

Victor Baker1 1) Dept. of Hydrology and Atmospheric Sciences, The University of Arizona * Victor Baker, [email protected]

The recent, large number of extreme flooding disasters raises questions about the possible role of climatic change. In many cases recent flood extreme magnitudes exceed decadal-scale stream gaging and century-scale historical records. Scientific understanding of extreme flooding absolutely demands real-world data on actual extreme flood events, but this type of data is not provided by either the flood-frequency analysis (FFA) or the mathematical modeling methods (MMM) that totally dominate conventional hydrological science/engineering practice. FFA methods unrealistically extrapolate from small, common floods to provide estimates for unknown, causally unrelated extremes; and MMM cannot create real-world data on the most extreme flooding. It thus follows that truly scientific flood hydrology must pay close attention both to those very rare cases when flood extremes happen and to the existing, very extensive wealth of natural evidence of flood extremes that actually have happened. Paleoflood hydrology provides real-world data on past flood extremes on the millennial time scales that insure representation of the most extreme flooding phenomena. Though miniscule resources have been devoted to this type of flood hydrological science (in comparison what is devoted to conventional FFA and MMM), a survey of existing global paleoflood data, collected by the world’s relatively small cadre of dedicated paleoflood hydrologists, suggests the following preliminary conclusions: (1) recent extreme flood magnitudes are NOT “unprecedented” -- similar extreme flood magnitudes appear in sufficiently long paleoflood records; (2) flood information from the deep past is NOT made irrelevant because of “nonstionarity” in regard to future changes (it is FFA that needs to change, NOT nature); and (3) while future climate change may result in different levels of flood intensity and frequency in particular catchments, these will most probably result from shifts in storm tracks or patterns, evidence for which can only be found in the long-term records of the past.

ID: 02167, 02.- Quaternary climate and environmental change in the Southern Hemisphere, (Oral)